1. Field of the Invention
The present invention relates generally to wear resistance of an object and more particularly, to a method of making a calcium-fluoride layer formed on an object surface for more wear resistance.
2. Description of the Related Art
Fluoride is a natural element and exists in many common eatable foods, such as tea, taros, seafood, and drinking water. Fluorine has high affinity for calcium and can invert calcium hydroxyapatite of dental enamels into calcium fluoroapatite having lower solubility to further reduce the solubility of the dental enamels in an acid. Fluorine can also be linked up with calcium ionized by the acid to jointly return to the dental enamels, as known as remineralization.
The aforesaid conventional way of increasing the wear resistance of an object is to coat fluoride to a part of the object. However, the calcium-fluoride layer on the surface of the object is soft and has poor wear resistance, so it is necessary to frequently coat the fluoride to the object. Besides, after the calcium-fluoride layer suffers wear and tear, the surface of the object becomes inaesthetic.